1. Field of the Invention
The invention concerns a method and compositions for lightening the color of skin.
2. The Related Art
Ever since the first freckle or hyperpigmented spot appeared on the human face, there has been demand for treatment. Historically treatments have involved preparations of mercury, plant extracts and even lemon juice. Bleaching of skin with ammoniated mercury and other salts of this metal are reported to be quite effective. Of course there are significant safety issues involved with mercurials.
Zinc peroxide has been utilized in anhydrous ointments as a bleaching agent. Monobenzyl ether of hydroquinone was marketed for its skin lightening effect but questions of safety were here also raised.
Ascorbic acid preparations, either pure or made from some natural material, such as lemon juice, were suggested as useful. While seemingly entirely safe, they do not seem to be very effective.
U.S. Pat. No. 4,096,240 (Mathur) refers to niacin as effective in skin lightening. This material is postulated to operate by retarding melanin dispersion or distribution into the epidermis. Since unpleasant skin flushing occurs with niacin, the patent suggests use of niacinamide as a substitute. Compositions based upon niacinamide are effective, but only to a limited extent.
Accordingly, it is an object of the present invention to provide a skin lightening composition and actives to accomplish this function which are more efficient than materials heretofore known and are safe to use.
Another object of the present invention is to provide a skin lightening composition and actives to accomplish this function which are particularly effective against agespots, freckles and hyperpigmentation.
These and other objects of the present invention will become more readily apparent from consideration of the following summary and detailed description.